As the wireless transmission of sensitive data has become more pervasive, encryption techniques are increasingly used to maintain the confidentiality of information flowing across radio frequency links. Generally speaking, current security methods depend upon the confidentiality of stored secrets. An attacker may or may not be successful in learning the secrets from encryption hardware or software via microprobing or other well-known types of attacks. However, the secrets may be exposed using non-technical methods such as physical threats, extortion, and bribes, among others.
Effective authentication methods may therefore assume that the stored secrets have been revealed. Once the secrets are revealed, powerful software tools are readily available to an imposter who may attempt to emulate suspected cryptographic paths and techniques in order to imitate a legitimate user entity.